Electric metal-working apparatus



T. K. ENGER. ELECTRIC METAL WORKING APPARATUS.

APPLICATION FILED APR. 6, 1920. T

Patented Nov. 9, 1920.

2 SHEETSSHEET l.

T. K. ENGER.

ELECTRIC METAL WORKING APPARATUS.

APPLICATION FILED APR. 6, 1920.

Patented Nbv. 9, 1920.

'2 SHEETS-SHEET 2.

. 720/47 $151 /1/ 9 mm w;

UNITED STATES PiTENT OFFICE.

THOBBJRN KJ'US ENGEB, OF LEIBSUND STA., CHRISTIANIA, NORWAY, ASSIGNOB TO THOMSON ELECTRIC WELDING COMPANY, 01 BOSTON, MASSACHUSETTS, A, CORPO- RATIO)! OF MASSACHUSETTS.

ELECTRIC METAL-WORKING APPARATUS.

Specification of Letters Patent.

Patented Nov. 9, 1920.

Application filed April 8, 1920. Serial No. 371,839.

To all whom it may concern: I

Be it known that I, TgORBJgdRN K. ENGER, subject of Norway, and temporary residence Leirsund Sta, Christiania, Norway have in- 5 vented certain new and useful improvements in Electric .Metal-Vorking Apparatus, of which the following-is a specification.

My invention relates to that class of elec-" volume of current on the secondary of a transformer organized for this class of work, a large inductive reactance is introduced which causes the current in the primary cirapplied to the primary so that the machine has a very low power fa'ctor,--in practice rarely above fifty per cent.

' The object of the present invention is to better the power factor, lower the cost of operation and generally increase the efiiciency .of the machine by utilizing a condenser, preferably of the static type, in such a way as to neutralize the inductive reactance of the transformer and thereby obtaining a current which will more nearl be in phasewith theapplied voltage of the primary. I

A further object of my invention is to secure'a sufficient operating voltage for a static condenser when such is employed in this manner.

In the accompanying drawings:

Figure 1 is a side elevation of a transformer havin a single-turn secondary and provided wit a condenser-employed according to my invention.

Fig. 2 isa diagram of circuits of the ap-' paratus. so

tion in the manner of applymg the condenser and securing efiicient operating voltage for the same.

i A indicates the frame of the machine,

, tactor Owing to the small voltage and large cuit to lag excessively behind-the voltage Fig. 3 shows diagrammatically a ,modifica-' B B legs or supports therefor, C the core of the transformer and D the one-turn lowvoltage secondary. E indicates the rimary and a static condenser connecte across the mains supplying the primary and in series with an auxiliary winding F connected in series with the main primary windin as shownmore particularly in the diagram i 2. Other parts indicated in Fig. 1 and Wllifil may be of the ordinary construction, are the support for the static condenserindicated at H, a regulatin switch I, lead cables J, conanel main line L and ush button switch for closing the circuit t at actuates the contactor panel.

As the most eflicient operating voltage for the static condenser is found to be much higher than that of the primary winding of the welder which in practice may be either 110, 220, 330, 440, or 550 volts or some odd voltage between any two of them, the auxiliary coil is emplo ed as a booster coil to step up the volta e o the condenser to its effec tlve value. aid auxiliary or boostercoil, as described, preferably utilizes the main transformer core instead of a separate transformer core, the whole primary winding being then in effect the primary of the altered transformer and the auxiliary winding being of suflicient turns to make up, when operated in series with the primary, the voltage desired as the effective value of the volts for the condenser. Y

When the invention is applied, however, to an old ,welding machine, it can be installed separately an a separate auto-transreactance by means of the condenser to over come the inductive ractance of the a paratus resulting from the construction 0 the secondary for low voltage heavy currents, an approachto a unity power factor can be obtained and the general efiiciency of the heater greatly increased,-say from thirty to fifty per cent. depending upon the amount of power factor correction to be made. Hence a given welder may be made to handle work from thirty to fifty per cent. greater in cross-section or for a given size o'fwork a machine from thirty to fifty per cent. smaller can be used.

Furthermore, by the use of my invention, surges on the feeder line may be greatly reduced thus minimizing the fluctuations of the line voltage and its disturbing influence on other apparatus on the line. Recording instruments in the power house will show a smoother curve and the power house operator is able to take on an additional load on a feeder operating the machine, thus increasing his income.

What I claim as my invention is l. The combination of an electric transformer constructed to supply heavy current of low voltage for heating purposes and a condenser connected to said transformer to neutralize the inductive reactancethereof.

2. The combination of an electric transformer constructed to supply heavy current of low voltage for heating purposes and a static condenser connected to said transformer to neutralize the inductive reactance thereof and a booster coil connected into the circuit of said condenser.

3. The combination with a transformer having a secondary adapted to supply cur rent of low voltage and large volume for heating purposes, of a condenser connected to the transformer and an auxiliary coil denser Wound upon the transformer core in series with the primary and adapted to increase the voltage of the condenser.

4. The combination with a transformer supplying from its secondary current of large volume and"low voltage and a conconnected to said transformer through a coil operating after the manner of a booster coil in an auto-transformer.

5. The combination of an electric transformer constructed to supply heavy current of low voltage for heating purposes, a static condenser connected to sa d transformer to neutralize the lnductive reactance thereof and a coil wound on the transformer and.

connected to the condenser.

G. In an electric metal working trans former, the combination of a core, a secondary on said core [for supplying heating current, a primary on said core the terminals of which. are connected to a condenser and tapped connections on said primary connected to the energizing current.

Signed at Christiania, Kingdom of N01- way, this 30th day of January, 1920.

THORBJWRN KJUS ENGlCR.

\ Witnesses:

NORTH A. HEDEHSCHON,. ROBERT H. FRAZIER. 

